I’ve been keeping a wary eye on the fires in Colorado, including one north of me, one south, and one way too close for comfort: the Flagstaff fire. This one crept over the foothills just southwest of Boulder and was pretty threatening there for a day or so, but it looks to be under much better control now, and firefighters think they’ll have it fully contained very soon. It was started by lightning, which is ironic since a few rain showers helped keep the fire under control as well.

Boulderite Dustin Henderlong took some amazing time lapse footage of the fire showing how much smoke was pouring out. The shots at night are, well, lovely, as much as I hate to say it.

The footage runs from 3:00 p.m. local time on Tuesday June 26 to 10:00 a.m. on Thursday. We’ve had some "spot" fires caused by more lightning strikes since then, but they’ve been taken care of quickly and efficiently by the amazing firefighting force deployed.

Not long after the fires started I was able to see the plume of smoke and water vapor from my house, nearly 10 km away:

As I mentioned in an earlier post, the thick parts of the smoke are red and the outer parts blue. A lot of that is due to the way light interacts with the particles in the smoke; blue light gets easily scattered away near the edges, but red light penetrates more deeply.

Just hours after the fire started, the plume had two pieces: a darker smoky part blowing east, and a lighter, bluer one that went up higher and got caught in more northerly winds. That blew it over my house, and I took this shot facing north, away from the fire – indicating just how far-reaching this was:

This plume was incredibly blue to the eye, more so than you can even see in this picture. It was amazing.

Oh- I need to mention a mea culpa. In that earlier post, I said the whitish plume from the High Park fire north of me in Fort Collins was from water vapor, probably from efforts out put the fire out. My old friend Al Janulaw pointed out what should’ve been obvious to me: when you burn an organic molecule (something based on carbon and usually containing lots of hydrogen and oxygen) one of the resulting byproducts is water (the hydrogen and oxygen combine to form H2O). So the water vapor plume is actually due, ironically, to the burning itself!

I had to chuckle when he wrote me; I should’ve thought of that myself. I love chemistry, but it’s been a long time since I took a class in it, and for whatever reason this obvious water source slipped my mind. It just goes to show you that even a science lover can have a lapse. Thanks to Al for pointing this out!

Finally, as the fire now appears to be on the wane, I’d like to thank everyone who sent notes via email and Twitter asking if I was OK. These fires are all pretty far from where I live, so we’re fine. I wish I could say the same for the folks in Colorado Springs, where it’s nothing less than apocalyptic. But I want to mention all the amazing brave men and women who have been fighting these blazes, especially considering they’re doing so in the incredible heat we’ve been getting, with temperatures commonly getting above 35°C (95+°F). We toss the word "hero" around a lot, but the thing is, they do exist. And I thank them.

I live in Southern California about 30 miles east of Los Angeles. Around 2003/4, we had fires everywhere and I remember turning onto a street in the middle of the night and seeing the ridgeline of the foothills and mountains ablaze. It was beautiful, but very somber. Ash covered everything and even got to the point where I was wearing a mask to go outside.

The fires destroyed a hiking area that my friends and I used to visit. As of last month, it is still closed from the damage. Maybe next year?

It is devastating, but a necessary part of living in a closed system. I am glad that your family is safe. Don’t forget to clean out the air filters in your cars and HVAC systems.

I’m reminded of a puzzle asking how to tell when a power plant is burning coal vs oil. When burning oil, some of the “smoke” is really steam that will seperate from the “ash” smoke. But coal is purely smoke(ash), no steam. The CarTalk guys, “Clik and Klak” (Tom and Ray), once asked this on their program. There was a university dorm (nearby) with “co-generation” that could burn either and I once saw this effect watching the smoke from its chimney at different times. Never thought I’d see it from a forest fire, though, just didn’t think about it deeply enough. I sure hope the fires in CO are under control, or at least will be soon.

If you have rain RADAR that you can look at you will see the plumes coming from the hotspots as what appears to be light rain. We’ve used rain RADAR here in Oz to give us rough positions of fires in Nation Forests. If it’s a hot travelling fire you will see it progress on RADAR time lapses and see what direction the plume is going.

Extremely interesting video. The fire behavior is what I would have expected… large plumes coming up in the afternoon and evening, then laying down at night into early morning. And the fact on the 2nd day when it was cloudy, the fire didn’t blow up nearly as much due to the temperature drop. Then in the late afternoon, the wind reversing up slope as the hot air rises.

This is a wind driven more than a terrain driven fire. It is very steep there and would be an absolute bitch to fight from the ground. I didn’t see any aircraft attacking it, but it may be far enough from civilization to let it burn for awhile.

I have friends who have a home that is technically in Grand Lake, but nearer Tabernash. J says that it’s just on the other side of the ridge, but they’re hoping the ridge keeps the fire on the other side (firebreak). Their important papers and photos are already in a tub near the house door, all they need to do to bug out is grab the cats, the dog and the tub (last summer fire got way closer, and they’re in the middle of an area really badly hit by the pine borer.)